Coating composition



United States Patent 3,086,871 COATING COMPGSITION David B. Sheldahl, Griffith, Ind, and George Entwistle,

Qhicago, 111., assignors to Sinclair Refining Company,

New York, N.Y., a corporation of Maine No Drawing. Filed Sept. 28, 1959, Ser. No. 842,599

7 Claims. (Cl. 106-14) This application is a continuation-in-part of application Serial No. 759,849, filed September 9, 1958, now abandoned.

The invention concerns a coating composition which gives long-lasting protection against corrosion to coated metal surfaces, especially chromium plated, or stainless steel surfaces. The composition contains about to 80% water, about 1 to 80% low-boiling hydrocarbon, about 0 to 9% high-boiling petroleum hydrocarbon, about 0.5 to boiled linseed oil, about 1 to 10% petroleum paraffin wax having a melting point of about 125 to 145 F., and about 0.1 to 2% sorbitan mono fatty acid ester, about 0.05 to 1% of a sulfonate selected from the group consisting of oil-soluble ammonium aromatic sulfonate, and an oil-soluble sodium aromatic sulfonate, about 0 to about 1.0% of an antioxidant, 0 to about 1.0% of a germicide and 0 to about of an antifreeze agent.

The coating composition of this invention is designed to plug the naturally-occurring cracks and pores in chrome plate, leaving behind a surface film which detracts to a minimum degree from the bright chromium .surft'ce, although it has protective and lasting properties comparable to thick coatings. This surface film can be polished after evaporation of the solvent. It has been shown that the composition is more effective when water is present. The linseed oil content gives a tougher film, curing to a hard fininsh. The wax component acts as an emulsifier and also gives barrier protection as well as overcoming stickiness due to the linseed oil. Water is usually included in the composition in a range of to 80%, but when the composition is to be applied as an aerosol about 5 to 10% water is then advisable. The low boiling liquid hydrocarbon is one which boils in the gas oil range or below, e.g. kerosene, naphtha, gas oil, etc. A preferred hydrocarbon is alkylate solven -the product formed when a C or C olefin is alkylated with isobutane. As an example, this product may have the following typical physical properties:

Gravity, API 52.1 100 m1. distillation:

Initial B.P. F 368 10% F 388 50% F 40 2 End point F 476 Flash, Pensky-Martens F 145 The high boiling point petroleum hydrocarbon is of lubricating oil viscosity and preferably is a Mid-Continent neutral oil. Since the ammonium mahogany sulfonate is frequently made in oils of this type the quantity of high boiling petroleum hydrocarbon, if any, can be conveniently supplied to the composition by using the total mixture formed in the manufacture of the ammonium sulfonate.

The aromatic sulfonates useful in this invention are the oil-soluble NH -aromatic sulfonates and oil-soluble sodium aromatic sulfonates of the benzene or naphthalene series, in which the aromatic ring is sulfonated and, in order to impart oil-solubility, the ring preferably also contains one or more'alkyl substituents having up to a total of twenty carbon atoms. Such sulfonates can be made by the ammonium hydroxide or sodium hydroxide neutralization of sulfonated aralykyl hydrocarbons such as :dinonyl naphthalene, and include neutralized sulfo- 3,086,871 Patented Apr. 23, 1963 ice nated bottoms from the manufacture of dodecyl-benzene, neolene, etc. fractions. Typical aromatic sulfonates are described for instance in US. Patent 2,594,266. They can be obtained by the reaction of ammonia or sodium hydroxide with sulfuric acid-treated hydrocarbon oils. Such mahogany sulfonates possess appreciable solubility in both water and hydrocarbon oils. In manufacturing the supplement of the invention, the sulfonates may be employed as a concentrate in the oil from which they are derived. A typical concentrate for use in this composition has, for example, a sulfonate concentration of about 10% by weight and can be prepared by treating a Mid-Continent neutral oil with four successive dumps of oleum, a total of pounds of the oleum being used for each barrel of oil. Following removal of the separable sludge after the last dump of oleum, the acid oil is blown with air to remove sulfur dioxide and settled to remove substantially the last trace of sludge. Thereafter the oil is mixed with 0.5% by weight of water and neutralized with an excess of anhydrous ammonia. Finally the oil is heated to a temperature of 280 F. to dehydrate it, and filtered to obtain the product.

Although the sulfonates are advantageously employed in the oil solution in which they may be prepared, the sulfonates can be recovered by extraction with a low molecular weight alcohol, such as isopropanol or ethanol, followed by distillation for use in the oil-free form. Aniline or a lower molecular weight oil-soluble alcohol, such as isopropanol, is advantageously added to sulfonate solution in small amounts to improve the stability thereof.

The petroleum wax may be paraffin or crystalline wax melting in the range from about to F.

The fatty acid mono esters of sorbitan useful in this composition are obtained by the esterification of sorbitan with fatty acids containing from 6 to 18, preferably at least 12, carbon atoms. The fatty acids can be those derived from various animal and vegetable oils and fats or synthetic fatty acids. Examples of suitable acids are caproic, caprylic, capric, lauric, myristic, palmitic, oleic, linoleic, linolenic, ricinoleic, stearic and dihydroxy stearic acids. Sorbitan is the partially dehydrated polyhydric alcohol l,2,3,4,5,6-hexanehexol. The esters are made by reacting 1 mol of the polyhydric alcohol or 1 mol of the partially dehydrated alcohol with one to three mols of carboxylic acid or carboxylic acid mixtures either in the presence of or absence of a catalyst and/ or hydrocarbon solvent. The catalyst may be acidic, for example, sulfuric or phosphoric acid, or alkaline, like sodium hydroxide. The ingredients are commingled and heated in a kettle or other container, preferably closed and equipped with suitable agitating means, at a temperature of to 300 C. until the reaction reaches the desired stage. It is frequently desirable to maintain an atmosphere of inert gas such as nitrogen or carbon dioxide over the reacting mass or pass the inert gas through the reacting mass in order to assist removal of water and prevent discoloration of the esters formed. The reaction may also be carried out while refluxing hydrocarbon solvent, with means provided for trapping out the water formed. These esters are well-known to the art and methods for their preparation have been described for example in US. Patent 2,322,820. These esters are commercially available in the Span series. Span 20 is sorbitan monolaurate; Span 40 is sorbitan monopalmitate and Span 60 is sorbitan monooleate. Span 80-" is a mixture of sorbitan mono fatty acids made from commercial fatty acid mixtures and contains sorbitan monostearate. In addition, these esters are available in less highly refined form in the Atpet series. Atpet 100, for example, is a dark red oily liquid having a specific gravity of 0.98 to 1.00, a minimum viscosity at 25 C. of 900 cp., an acid number of less than 7, a hydroxyl number of 160 to 185, a saponification number of 140 to 155 and a pour point of 50 to 85 F. Atpet 200 is a sorbitan partial fatty ester. It is an amber-colored oily liquid having a specific gravity at 25 C. of approximately 1, a viscosity at 25 C. of approximately 1000 cp., an acid number of 4 to 8, a hydroxy number of 180 to 205, a saponification number of 135 to 150, and a pour point of approximately F. Span and Atpet are trademarks of the Atlas Powder Company.

If desired antioxidants can be incorporated into the compositions of the present invention. The presence of an antioxidant is preferred mainly for the reason that it protects the linseed oil component of the novel composition against oxidation. Suitable antioxidants for use in the present invention are the alkyl substituted phenols such as 2,6-ditertiary butyl, 4-methyl phenol; 2,4,6-tri tertiary butyl phenol; ortho tertiary butyl phenol; alkyl substituted nitrogen-containing phenols such as n,n-butylp-aminophenol; isobutyl-p-aminophenol and n,n-di-secondary butyl phenylene diamine. The above antioxidants are to be considered as merely exemplary and as not limiting the use of other antioxidants that are effective in hydrocarbons.

Germicides, likewise, if desired, can be used in the present invention. Use of a germicide is preferred, however, for the purpose of protecting the sulfonate component of the present invention against attack from bacteria. The germicides useful in our invention are those effective against bacteria known as the sulfate reducing or anaerobic type. The germicides include but are not limited to the following types: halogens, phenols, heavy metal salts, acids triphenylmethane dyes, amines and aldehydes. By a halogen'type germicide we mean to include halogens such as iodine and organic halogen compounds such as organic chloramines, e.g. Chloramine- T, a commercial germicide in which the active ingredient is sodium para-toluene sulfonchloramide, and chlorobenzenes, e.g. Cuniphen 2722, a commercial germicide in which the active ingredient is 2,2'-methylenebis (4- chlorophenol). By a phenol type germicide we mean to include phenols such as ortho-cresol and thymol (l-methyl-3-hydroxy-4-isopropyl-benzene), and halogenated phenols such as chlorinated phenols, e.g. Dowicide 6, a commercial germicide in which the active ingredient is tetrachlorophenol and Nalco 21-8, a commercial germicide in which the active ingredient is trichlorophenate and sodium pentachlorophenate. By a heavy metal salt type germicide we mean to include heavy metal salts such as copper salts, e.g. Cuprose, a commercial germicide in which the active ingredient is copper citrate, and organic mercury compounds, e.g. mercurochrome. By an acid type germicide we mean to include acids such as boric acid and 2,4,5-trichlorophenoxy acetic acid. Examples of triphenylmethane dye type germicides include dyes such as malachite green. Examples of amine type germicides include amine type compounds such as Nalco X- 234, a commercial germicide comprising 1-(2-hydroxy ethyl)-1-benzyl-2-tridecyl imidazolinium nitrite in an alcohol co-solvent. It is non-phenolic and contains no heavy metals. Examples of aldehyde-type germicides include formaldehyde.

Although unnecessary, the use of anti-freezes in the present invention can be desirable particularly in cold climates. Suitable alcohol anti-freezes are the glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and the lower monohydric alcohols such as methyl, ethyl, propyl and butyl alcohol.

It is preferred to have the ingredients present in the approximate ranges:

Percent Water 50 to 80 Low boiling hydrocarbon to 30 High boiling petroleum hydrocarbon lto 5 Boiled linseed oil 2 to 7 Percent Petroleum wax -a 1 to 5 Sorbitan mono gatty acid esther 0.1 to 1.5 Aromatic sulfonate 0.1 to 0.5 Anti-freezes 2 to 15 Anti-oxidant 0.05 to 0.5 Germicide .1 to l A specific formulation of the composition of the invention is:

Percent Ammonium mahogany sulfonate 0.3 Sorbitan mono fatty acid ester 1.0 135-137 F. M.P. parafiin wax 2.0 Boiled linseed oil 4.0 High boiling petroleum hydrocarbon 2.7 Low boiling hydrocarbon 25.0 Water 65.0

The above specific formulation can also include about 0.05 to 0.5% of an anti-oxidant, .1 to 2% of a germicide and 2 to 15% of an anti-freeze.

The following examples and tests are included to further illustrate the present invention.

A suggested way to prepare these coating compositions is first to mix the non-aqueous materials at about 150 F. and then add this mixture slowly to highly agitated water at about 150 F. and mix until an emulsion is formed. It is preferred, however, to mix the non-aqueous constituents to a temperature of at least about 135 F. and to add to this mixture with rapid stirring the water heated to a temperature greater than about 135 F.

EXAMPLE I Table I below shows the results of tests comparing the corrosion resistant qualities of the composition of the invention with other coating compositions.

Chrome plated automobile license plate fasteners were selected as test specimens. Metalographic examination determined the chrome plating to 'be a typical automotive chrome-plated product as to its thickness and application. The license plate fasteners were used both new and also after pre-nusting. The pre-rusted (old) specimens were reconditioned by acid cleaning to a corrosion-product-free surface before application of the polish. Because of a limited supply of stainless steel automobile porthole grilles, most of the testing was done with automobile license plate fasteners, but tests performed on the stainless steel specimens gave comparable results. The test specimens were exposed until failure, that is, until more than a trace of rust was observed, under three different conditions: (1) the regular MIL-L-3150 salt fog cabinet wherein ASTM synthetic sea water is fogged into a cabinet maintained at F.; (2) the same cabinet with the same conditions except deionized water was used instead of the synthetic sea water; and (3) immersion in ASTM synthetic sea water.

The formulations reported in Table I are as follows. Formula I consisted of an emulsion containing 1% Atpet 100, 3% of a solution containing 10% ammonium mahogany sulfonate in the petroleum lubricating oil in which it was manufactured, 2% paraffin wax (MP. to 137 F.), 44% alkylate, solvent and 50% water. III is an emulsion containing 1% Atpet 100, 3% of the ammonium mahogany sulfonate solution of formulation I, 4% boiled linseed oil, 2% parafiin wax (MP. 135 to 137 F.), 40% alkylate solvent and 50% water. II is a formulation containing 4% of a mixture containing 75% of the 10% ammonium mahogany sulfonate of Formulation I and 25% Atpet 100, 4% boiled linseed oil and 92% alkylate solvent. These formulations were compared with each other by coating a chrome-plated automobile license plate fastener with each and subjecting i to the test conditions described. Half a dozen fasteners were also coated each with a different automobile polish purchased at retail in the Chicago area. Typical test results for such a fastener are also reported, as well as the on one side of each of twelve automobiles was treated, once a month, either with Formulation III, a commercial wax, polish or cleaner, or given no treatment. The Chrysler, Cadillac I, Ford I, Chevrolet I, Buick and corrosive effects of the test conditions on a license plate 5" Plymouth I were coated about November 1 and the fastener which was not given any additional polish coatother models received their initial treatment in the latter ing. part of December. Various combinations of the com- ASTM synthetic sea water provides a solution conposition of the invention, commercially sold polishes, and taining inorganic salts in proportions representative of no treatment were thus tested side by side. The comocean water. The process by which this water is made mercial waxes and polishes tested are identified in the can be found on page 295 of the November 1957 Book table below as A3, B2, etc., the brands of the same manuof ASTM Standards on Petroleum Products and Lubrifacturer or distributor being given the same letter and cants. This standard synthetic sea water has a pH of different numbers. Liquid polishes have been given odd 8.2 and contains; numbers, while paste waxes are given even numbers. Comp0und /1' All the cars were washed at least every two weeks and Nacl 2454 generally at least once a week. The trim Was always MgC12.6H2O 1110 free of dust and dirt before any of the coatings Was so applied. Two of the cars were used to evaluate the excaclfi L16 perimental Formula II product described above. Table KCI 059 20 II shows the treatment given each car and condition of NaHCO3 010 the bright metal in the following May. 010 The trim of these cars received much better care than H3303 0 average and one would not expect much deterioration. SIC12.6H2O 0 However, close inspection of the trim shows that fre- NaF 00 quent washing alone will not prevent trim corrosion and the use of presently available commercial products, bl 1 while slowing down the corrosion process, will not consistently arrest it completely. Chrome'plated die cast- TEST RESULTS CHROME AUTOMOTIVE PARTS ing appears to be the most easily corroded of all bright Failure time days metal trim and the composition of the invention gives excellent cororsion protect-ion to automobtile bright metal trim. Samog Waterfog Formulation IV, an emulsion of 30% water, 60% alkylate solvent, 3.5% paraffin wax (M.P. 130132 F.), Test specimens New Old New Old New Old 2.5% boiled linsed oil, 3% ammonium mahogany sulfonate concentrate (10% sulfonate, remainder petroelum Formula: lubricating oil) and 1% Span 80, and Formulation V, an

3+ 2 3+ 2 g g emulsion of water, 3% parafiin wax having a meltrri' 14+ 8 11+ 30 30 ing point of 13 8 to 140 F., 0.5% Span 80, 0.1% aml: i L t i: 40 monium mahogany 'sulfonate, 6% boiled linsed oil and the rest :alkylate solvent also give satisfactory performance 1 No rust or only a trace of rust when test was discontinued. 3 Tin-eventing corrosion of chromium Plated mOfiVG Table II RESULTS OF CHROME PRESERVATIVE TESTS ON CARS Treatment and bright metal trim condition Make oi automobile Coating Drivers side Coatmg Passengers side Chrysler N 0 change since start of test Chrome-plated die casting erupted further.

Cadillac 1.. d Do. I

F d 1 Stainless steel trim spotted.

Chevrolet I Rust on wrap-around portion of front and back bumpers; rust on bumper over tailpipe; stainless steel trim spotted.

Chevrolet II A1 Light patches of rust on rear bumper III Good condition.

Buick B2 Chrome-plated die casting erupted further- III No change since start of test.

De Soto. None Patches of rust on bumper over tailpipe III Good condition.

Plymouth r B2 Good condition None.-- Patches of rust on rear bumper below license plate,

Plymouth II-.. A3 do -d0 R sted areas on rear bumper; chrome-plated die casting erup e Cadillac II A2 Chrome-plated die casting erupted L Good condition.

Lincoln II Good condition except for a residual st ky film. A3 Chrome-plated die casting erupted.

Ford II A3 Good condition II Good condition except for a residual sticky film,

1 A section of plating on the right rear fender was completely peeled off and was heavily rusted before the test. 1 A section of plating on the left front fender was completely peeled off but apparently d1d not rust.

It can easily be seen that Formulations II and III which contain boiled linseed oil give far longer-lasting corrosion protection to chrome-plated surfaces than the average commercially sold automobile polish, and Formulation III also gives markedly better protection than Formulation I, which did not contain boiled linseed oil, or Formulation II, which did not contain water or wax. Formulation II, which did not contain wax, was found to bediflicu-lt to apply. Formulation III, however, was satisfactory as to its application characteristics.

Road tests.Cars were field tested in the Chicago The mixing speeds and temperatures employed have a definite effect on the emulsion stability and corrosion metropolitan area during the winter months. The trim preventive properties of the coating composition of the present invention. The non-aqueous constituents should be heated above about 135 F. to assure solution of the paraflin wax. A temperature of about 150 F. is generally chosen to make sure complete solution is obtained before the water is introduced. The water when added should be at a temperature above about 135 F., preferably about 150 F. Formulations wherein the Water is less than 135 F. when added are not as stable or as effective as corrosion preventives as the formulations where the water was 135 F. or higher. Furthermore, formulations limited to about 50 to 80% water are not only the most stable emulsions but posses best corrosion preventive properties. Also, as will be demonstrated, when faster mixing speeds are used a better product results.

To illustrate the advantages of adding water to the non-aqueous constituents in accordance with the preferred method of preparation rather than the non aqueous constituents to the water, Examples 11 to V are included.

EXAMPLE II Formulations containing 2% paraifin wax (135 to 137 F., M.P.), 4% of a mixture composed of 75% of a solution containing ammonium mahogany sulfonate in the petroleum lubricating oil in which it was manufactured and 25% Atpet 200, 4% boiled linsed oil, various amounts of water, with the balance alkylate solvent, were prepared either by adding the non-aqueous constituents to the water or adding the water to the non-aqueous constituents. In all cases the non-aqueous constituents were mixed together at 150 F. and the temperature of both the water and non-aqueous constituents before admixture was 150 F. Addition, whether of water to hydrocarbons or hydrocarbons to water was conducted slowly to assure an emulsion. Mixing of the non-aqueous constiuents and water was conducted at a speed of 12,000 r.p.m. and continued until the temperature fell to 130 F. These formulations were compared with each other by (1) coating metal panels with the different formulations 'and subjecting the panels to the regular MIL-L- 3150 salt tog cabinet test wherein ASTM synthetic sea water is fogged into a cabinet maintained at 95 F. and (2) by measuring the percent of separation of water and oil from the formulation after three weeks of storage.

The results are illustrated in Table -III.

1 Test stopped at 48 hours.

2 Test stopped at 24 hours. EXAMPLE IV The formulation of Example '11 having 65% water and alkylate solvent was prepared in accordance with the method of Example II but using water of various temperatures during formulation. The test results are found in Table V. 7

Table V Temperature, F. Stability, MIL-L-3150 25 3 weeks salt fog test Sample No. 982- I storage results, per- Water Hydropercent cent rust at carbon oil sepa- 72 hours rated 75 150 5 10 100 150 4 3 125 150 3 2 135 150 2 None 150 150 2 None EXAMPLE v Formulations containing 2% paraffin Wax (135 to 137 F., M.P.), 4% of a mixture of 75 of a solution containing ammonium mahogany sulfonate in the petroleum lubricating oil in which it Was made and 25% Atpet 200, 4% boiled linseed oil, 65% water and 25% alkylate solvent were prepared in accordance with the method of Example I using various mixing speeds during admixture of the water with the non-aqueous constituents. The formulations were tested as in the previous examples. Results of the tests are shown in Table VI.

Table III Water-in-oil emulsion Oil-in-water emulsion Three weeks MIL-L- Three Weeks MIL-L- Percent water storage, percent 3150, salt storage, percent 8150, salt used Sample separated fog results, Sample separated fog results,

#982- percent #982- percent rust at 72 rust at 72 Water Oil hours Water 011 hours 249 2 5 5 250 5 35 166 2 2 3 172 35 Trace 10 165 None 2 None 171 25 Trace l 35 157 None 7 1 158 20 Trace 1 75 159 None 10 6 160 15 Trace 2 75 161 None 15 25 162 10 Trace 2 80 163 None 20 1 Hit 5 Trace 3 35 1 Test stopped at 48 hours. 2 Test stopped at 24 hours.

EXAMPLE III Table VI Formulations containing 2% paraffin wax (135 to Stability, Mnrlrmo 137 F., M. P.), 4% of a mixture composed of of a stirrer 3 Weeks Salt fog e t Sample No. 982- speed, storage, results, persolution contain-mg 10% of ammonium mahogany su-lpercent n centmstat fonate on the petroleum lubricating oil in which it was p ted 12 hours made and 25 Atpet 200, 4% boiled linseed oil, various amounts of water ranging from 2.5 to with the 588 g balance alkylate solvent were prepared by adding water i, g to the non-aqueous constituents as described in Example 51000 2 None II. As in Example 11 the formulations were given the 12,000 2 None .we ora e stabil't and the salt to" cabinet test. 3 ek st g l y c 1 Brookfield counter rotating mixer with 1% blades. Approximate These results are given in Table IV.

5 stirring speeds shown.

Examination of the test data shows the following:

The data of Table II demonstrates that much more corrosion protection is afiorded when the water is added to the non-aqueous constituents than when the reverse procedure is used. The preparation containing 65% water when prepared by adding water to the oil protected the mild steel panels 72 hours in the MIL-L3150 salt fog test, while the same formulation prepared by adding the oil to the water allowed the panels torust 35% in 48 hours. When other amounts of water, i.e. 50% to 80%, are present the differences in corrosion protection are also quite pronounced.

The data of Table IV demonstrates that 65 water content is the optimum for emulsion stability as well as corrosion preventive qualities. As the content of water decreases or increases both the emulsion stability and corrosion preventive qualities worsen. For optimum stability and activity the water content should be about 55 to 80%.

The effects of mixing speeds and temperatures are evident from Tables V and VI. The formulations in Table V wherein the water was less than 135 F. when added were not as stable or as effective as corrosion preventives as the formulations where the water was 135 F. or higher. It is demonstrated in Table VI that when faster mixing speeds are used a better product results.

EXAMPLE VI Formulations containing 2% parafiin wax (135 to 137 F., M.P.), 0.5% of the sulfonate indicated below in petroleurn lubricating oil, 25% Atpet 200, 4% boiled linseed oil, 65% water with the balance alkylate solvent were prepared by adding the water to the non-aqueous constituents. Metal panels were coated with each of the formulations and subjected to the salt fog cabinet test. The results were as follows:

1 concentrate ammonium mahogany sulfonate in Mid-Continent neutral oil from which it was derived. 4

2 10% concentrate ammonium mahogany sulfonate in Sweet Texas Distillate from which it was derived.

3 Oil-soluble sulfonic acid prepared by the sulfonation of the bottoms produced in the manufacture of monododecyl benzene which bottoms consist essentially of didodecyl benzene along with a minor amount of other polyalkylated benzene molecules.

4 Ammonium hydroxide neutralized sulfonated dinonyl naphthalene.

6 Neutralized sulfonate bottoms from the manufacture of benzene.

" Test stopped at 24 hours.

b Test stopped at 48 hours.

The results show that of all the sulfonates, better corrosion resistance in a salt Water environment is obtained when ammonium mahogany sulfonate is employed. This is not to be construed as meaning that the other sulfonates are poor corrosion inhibitors, however, for all of the sulfonates give satisfactory rush inhibiting properties outside of a salt environment.

EXAMPLE W1 A formulation containing 2% paraffin wax (135 to 137 F. melting point wax), 4% boiled linseed oil, 4% of a mixture composed of 75% of a solution containing 10% ammonium mahogany sulfonate in the petroleum lubricating oil in which it was manufactured and 25% Atpet 200, 0.3% of 2,6-ditertiary butyl-4-methyl phenol, 0.5% of ortho cresol, 65% water with the balance alkylate solvent 10 was prepared. Metal panels were coated with formulation and subjected to the salt fog test for 72 hours. No rust was found.

EXAMPLE VIII To the formulation of Example was added 8.0% of ethylene glycol. This formulation was tested as in Example VII and similarly no rust was found.

It is to be understood that the anti-oxidant, germicide and anti-freeze employed in Examples VII and VIII could be replaced by any of those listed in the specification. Similarly, the ammonium mahogany sul'fonate can be replaced by a sodium aromatic sulfonate.

We claim:

1. A coating composition consisting essentially of about 0.05% to 1% of a sulfonate selected from the group consisting of oil-soluble ammonium aromatic sulfonate and an oil-soluble sodium aromatic sulfonate, about 0.25% to 2% sorbitan mono fatty acid ester, about 1% to 10% petroleum paraffin wax having a melting point of about 125 to 145 F., about 0.5 to 10% boiled linseed oil, up to about 9% high-boiling petroleum hydrocarbon, about 180% low-boiling hydrocarbon and about 580% Water.

2. A coating composition consisting essentially of about 0.05% to 1% of a sulfon-ate selected from the group consisting of oil-soluble ammonium aromatic sulfonate and an oil-soluble sodium aromatic sulfonate, about 0.25 to 2% sorbitan mono fatty acid ester, about 1% to 10% petroleum paraffin wax having a melting point of about 125 to 145 F., about 0.5 to 10% boiled linseed oil up to about 9% high-boiling petroleum hydrocarbon, about 18-0% low-boiling hydrocarbon and about 5-80% water, about .05 to 1% of an anti-oxidant to protect said linseed oil against oxidation and 0 to 1.0% of a germicide to protect said sulfonate from bacterial attack.

3. A coating composition consisting essentially of approximately 50 to water, 10 to 30% low-boiling hydrocarbon, 1 to 5% petroleum lubricating oil, 2 to 7% boiled linseed oil, 1 to 5% petroleum paraffin wax (melting point to 145 F.), 0.1 to 1.5% sorbitan mono fatty acid ester and 0.1 to 0.5% of a sulfonate selected from the group consisting of oil-soluble ammonium aromatic sulfonate and oil-soluble sodium aromatic sulfonate.

4. A coating composition consisting essentially of approximately 50 to 80% water, 10 to 30% low-boiling hy-. drocarbon, 1 to 5% petroleum lubricating oil, 2 t0 7% boiled linseed oil, 1 to 5% petroleum paraflin wax (melting point 125 to 145 F.), 0.1 to 1.5% sorbitan mono fatty acid ester and 0.1 to 0.5% of a su -fonate selected from the group consisting of oil-soluble ammonium aromatic sulfonate and oil-soluble sodium aromatic sulfonate, about .05 to 1% antioxidant to protect said linseed oil against oxidation and about .05 to 0.5% of a germicide to protect said sulfonate against bacterial attack.

5. A coating composition comprising the following ingredients in approximately the following proportions:

Percent Ammonium mahogany sulfonate 0.3 Sorbitan mono fatty acid ester 1.0 -137 F. M.P. paraffin wax v 2.0 Boiled linseed oil 4.0 High-boiling petroleum hydrocarbon 2.7 Low-boiling hydrocarbon 24.7 Water 65.0 Anti-oxidant 0.3

6. A method of preparing the coating composition of claim 1 which comprises mixing the non-aqueous constituents to a temperature of at least about 135 F. and add ing to said mixture with rapid stirring the water heated to a temperature greater than about 135 F.

7. A water-in-oil emulsion composition consisting essentially of approximately 50 to 80% water, 10 to 30% 1 1 low-boiling hydrocarbon, 2 to 7% boiled linseed oil, 1 to 5% petroleum paraffin wax (melting point 125 to 145 F.), 0.5 to 1.5% sorbitan mono fatty acid ester and 0.1 to 0.5% of a sulfonate selected from the group consisting of oil-soluble ammonium aromatic sulfonate and oil- 5 soluble sodium aromatic sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS Zimm'er et 'al. July 10, 1951 Walker et a1 June 3, 1952 Paxton Aug. 3 0, 1955 Howell et al Nov. 22, 1955 Rudel et 'al Nov. 3, 1959 

1. A COATING COMPRISING CONSISTING ESSENTIALLY OF ABOUT 0.05% TO 1% OF A SULFONATE SELECTED FROM THE GROUP CONSISTING OF OIL-SOLUBLE AMMONIUM AROMATIC SULFONATE AND AN OIL-SOLUBLE SODIUM AROMATIC SULFONATE, ABOUT 0.25% TO 2% SORBITAN MONO FATTY ACID ESTER, ABOUT 1% TO 10% PETROLEUM PARAFFIN WAX HAVING A MELTING POINT OF ABOUT 125 TO 145*F., ABOUT 0.5 TO 10% BOILED LINSEED OIL, UP TO ABOUT 9% HIGH-BOILING PETROLEUM HYDROCARBON, ABOUT 1-80% LOW-BOILING HYDROCARBON AND ABOUT 5-80% WATER. 